Compensating blade clamp



E. REANEY Feb. 28, 1939.

- COMPENSATING BLADE CLAMP Filed Aug. 6, 1937 Patented Feb. 28, 1939 OOMPENSATING BLADE CLAMP Ernest Reaney, Stratiord, Conn, assig'nor to The 0. K. Tool Company, Inc., New York, N. Y., a corporation of New York Application August 6, lssm'seml No. 157,664

4 Claims.

The present invention relates to improvements in the clamping means for inserted blade cutters and has'for-its primary objective to obtain a firm clamping of the blade over an extensive area and particularly at regions close to the cutting edges'in all positions of blade adjustment.

A further aim of the invention is to obtain a firm clamping of the blade against its front, rear, and bottom sides by a single rectilinearly movable element and which clamping becomes more firm and rigid as the tooling forces acting upon the blade increase in intensity.

Still another objective of the invention is to obtain compound adjustments of the blade member, that is, an adjustment in two directions simultaneously in one resetting and thereafter to effect a firm clamping of the blade in the region of the cutting edges in its reset position of adiustment.

The invention further aims to render available a blade clamping structure whereby the .above ends may be attained and which may readily be adapted to single or multi-bladed cutters. by way of additional improvements, to render available an inserted blade cutter in which blades may be repeatedly and independently readjusted to compensate for wear and regrinding of the cutting edges, and which is constructed of relatively few parts of simple design and easy manufacture having all of the advantages of a solid cutter plus the additional advantages of com pound adjustment and blade replacement.

In realizing the aims of the invention, it is proposed to construct the cutting element in two parts, a blade member proper and'a locking member. Each element is tapered longitudinally'and also in a direction of its width and both elements fitting a complemental compoundly tapered and open sided recess formed in a body member. The general axis of the blade seating portion of the recess is inclined at an angle with respect to the general axis of the body so that when the blade member is adjusted longitudinally therein the cutting edges, formed at the projecting corner of the blade, advance forwardly and outwardly in a ratio dependent upon the angleof incline given to the blade seating surface.

The tapered locking member is adapted to lie adjacent the face of the blade and to move therealong in a direction transverse the longitudinal axis of the blade, that is to say, while the blade seating surface is inclined downwardly and rearwardly from the cutting end of the blade, the

upwardly relative to the blade. The relative lon gitudinal movement between the two members is such that one crosses the other.

Ineflectlng a clamping action, the blade and locking members are inserted in the recess with their wide longitudinal edges toward the bottom and outer ends and the blade adjusted longitudinally on its inclined seat to the position required. Thereafter the wedge is driven inwardly to clamp the blade between its front and rear surfaces. By reason of the longitudinal and transverse tapers on the blade, inward movement of the wedge tends to shift the blade longitudinally and simultaneously inwardly firmly to engage the lower seating surface. In this way the blade is eflectively clamped on three sides.

, As the cutting edges on the blade become dulled, the blade may be adjusted outward along the inclined seating surface thereby causing the outer cutting edges to be advanced "forwardly and laterally. The lock piece when next driven affect on the blade, further rearwardly and away from the cutting edges. This is a disadvantage commonly found in prior structures for the reason that the more distant is the clamping affect, the greater is the tendency toward vibration and chatter. Furthermore, as the lock piece progressively moves to the rear and the blade progressively moves forward as it becomes used up, the point is soon reached where the lock piece overlaps the end of the blade a substantial amount. This overlapping reduces the eifective clamping areas of the blade and lock piece to but a fraction of' their original amount and places this small fraction at the tail end of the blade instead of at the cutting end thereof.

The present invention overcomes these difliculties and maintains a firm clamping action at the forward end of the blade in all positions of relative adjustment of the members. These ends are achieved by interlocking the lock piece with the cutter body so that it may be stepped bodily laterally to bring the lower and wider longitudinal edge thereof nearer the smaller dimensions of the recess. Thus, as the blade member is moved outwardly and reduces in thickness, the lock piece is moved bodily laterally and in effect increases in thickness thereby compensating for the loss in blade thickness without changing its position in an endwise direction. With this arrangement the clamping action of the lock piece is maintained effective at the forward and cutting end of the blade throughout the life of the blade.

Other objects and advantages will be in part indicatedi'n the following description and in part rendered apparent therefrom in connection with the annexeddrawing.

To enable others skilled in the art so fully to apprehend the underlying features hereof that Figs. 3 and 4 are respectively end and side sec-' tionai views of the blade clamp in different positions.

Fig. 5 is a variant of Fig. 4.

Fig. 6 is a plan view, taken along line 66 of Fig. 3, illustrating the relation of the surfaces at the bottoms of a blade and lock piece slot formed in the holder.

The milling cutter disclosed in Figs. 1 and 2 illustrates a preferred embodiment of the invention and which comprises a base or body member 10 recessed on its front face at H to provide annular upstanding flange l2 within which blade slots l3, extending in a general radial direction, are formed. The back of the body is recessed and slotted as at In to fit a standard spindle.

As is usual with blade type of cutters, the blades are inclined with respect to the diameter approxi mately 10 as shown in Fig. 1 and also inclined relative to the axis approximately 15 as shown 'in' Fig. 2, in order to give the front face of the blade the proper cutting pitch relative to,the work. In accordance with this invention, the blades and corresponding blade slots l3 are given a further incline in their pitched plane of approximately 15 as illustrated in Figs. 2 and 4, for a purpose later to be explained.-

A blade member l4 provided with cutting edges l5 and H5 at its outer end, is adapted to be inserted in each of the. blade slots l3 and clamped therein by locking member l1. Preferably the locking member I! engages the front face of the blade, and to attain that relation an additional recess l8, in communication with the blade recess 13, is formed in the body member.

The blade and lock piece members are tapered longitudinally, the blade taper being approximately 2 /2, and the lock piece taper approximately 7, and the apposition side walls of the blade slot and locking member slot being correspondingly tapered. In addition to the longitudinal tapers on the members each member and adjacent side wall of the recess is alsotapered in a direction of its width. This transverse taper being, in the case of the blade, approximately 3, and in the case of the locking member approximately 10, and both members being positioned in their related recesses with their Widest edges toward the bottom and toward the outer or cutting ends.

As previously stated, the bottom wall I3 of the recess l3 inclines downwardly and rearwardly. The bottom wall 18 of the wedge receiving recess, however, extends rearwardly and upwardly relative to the bottom wall 13 with the result that as the wedge piece moves inwardly in a direction of its longitudinal axis c, d, it crosses the longitudinal axis a, b, of the blade member. B'y virtue of the transverse taper on the blade, longitudinal movement of the wedge inwardly tends to urge the blade member downwardly firmly against its seating surface 13. Longitudinal movement of the blade member is resisted during the clamping action by reason of .the longitudinal taper formed upon the back surface of the blade. The net result being, that the blade member is clamped firmly at its front, rear and bottomsides by the action of a transversely moving wedge piece. The clamping action, it will be seen, becomes more firm as the tooling forces acting upon the cutting edges l5 and it increase, for in that event, the blade member is also urged in a clamping direction.

To compensate for wear and regrinding of the cutting edges l5 and IS, the blade member is re-.

leased from the body and adjusted outwardly along the incline surface l3, which has been predetermined to effect an advance of the edges l 5 and IS in a ratio commensurate with the rates at which those edges wear and require resharpening. When the wedge piece I! is reinserted it would ordinarily take up a position further rearwardly as represented in dotted lines I! in Fig. 5 and the efiect of its clamping action on the blade as shifted from the region marked to the region marked 11 in Fig. 5. The further away this clamping region is from the cutting edges of the blade the less secure is the blade clamp. Furthermore, as the tail end I4 of the blade progresses upwardly along the inclined seating wall l3, it finally will reach a position .2 wherein the wedge member considerably overlaps the end of the blade and, the total clamping area on the blade is reduced to the small fraction indicated by the area e in Fig. 5, and this fraction appliedv at the extreme tail end of the blade instead of at its forward end. 7

A further disadvantage experienced in moving a wedge piece longitudinally the entire distance necessary to take up the loss in blade thickness is, that a substantial portion of the slot represented by the area f in Fig. at the cutting end of the blade remains open. This opening will not only become jammed with chips but be severely mutilated by their cutting action, and in consequence when blade replacements are to be made, the wedge members no longer fit their recesses properly and insecure clamping results.

In order to eliminate the foregoing disadvan tages, it is proposed to interlock the wedge member I! with the body member by a series of interfittingformations such as serrations 20 extendingbetween the adjacent faces of the wedge and body members. Preferably the serrations are relatively fine pitch, having an included angle of approximately 90 and a spacing of approximately .03, or approximately thirty-four to the inch. The interfitting serrations extend in the direction of the longitudinal axis of the wedge piece, that is,

' parallel to the line 0, d, in Fig. 4, and which in cooperation with the transverse taper on the wedge affords lateral adjustability and a means for compensating for the loss in blade thickness without shifting the wedge inwardly the distance normally required to take up that loss.

piece would not move inwardly as far as it did originally. However, as the blade member, reduces in thickness as it moves outwardly and therebyin effect increasing thedimensions of the recess, the bodily lateral movement of the When the wedge is again driven home it occupies substantially the same position in an endwise.

direction as it did originally. This results in maintaining a-firm clamping action at the forward end of the blade, in all positions within the normal life of the blade, while at the same time affording clamping action over' a relatively large area by reason of the fact that the wedge member remains, in effect stationary and onlythe blade moves, whereas, in thevarlant disclosed in Fig. 5, both members move. I

This mode of adjustment also has the further advantage that that portion of the blade" and wedge receiving recess-adjacent the cutting edges remains effectively closed under all positions of blade adjustment.- Hence, the chips incident to the cutting operation cannot iorce'their way into the aperture and mutilate or-enlarge' the opening.

By arranging the axis of movement of the blade and wedge members at an'angletoeachother, as indicated in the drawing, and by start- ,ing thelower wall l8 of the wedge receiving recess at a point such that it will intersect the wall l3 of theblade recess approximately midway its end, the effective clamping area of the wedge'increases as it is stepped laterally out-.

ward. To obtain this result a lateral clearance space 2| entering the lower supporting wall l3- of the blade recess must be provided for the overlapping lower wedge portions. This clearance aperture 2| disappears at the point of intersection 22 of the lower walls It and II.

A tool holder embodying the foregoing explained clamping principle has the further advantage that the blades, in the case of a multiis capable of independent adjustment.

' specific cutter illustrated in the drawing, it will bladed cutter, need not be all of the same length initially and it matters not whether the respec:

tive blades due to some inherent property or non-uniformity in their heat treatment, wear differently or dull faster than others, for each blade In the be seen that although the wedge members ,are

driven inwardly in a radialdirection, the tendency of the body to split whereby succeeding blades project different distances, is effectively eliminated by reason of the closed peripheral por- 'tions of the body member proper. As shown in Fig. 2, theblade slots are relatively shallow as compared to the axial length of the body mem-' ber which portion may be left in the solid.

The incline of the blade slots and also of the end surface l2 of the body not only provides an exaggerated relief for the major portion of the blade so that it does not rub on the surface being machined but provides ample clearance space for the chips and freedom in their movement to- The incline of the blades in the plane of their pitch makes it possible to use relatively narrow stock for the blades while nevertheless affording amplematerial for regrinding operations.

Without further analysis, the foregoing will so fully reveal the gist of this invention that others can, by applying current knowledge, readily adapt it for various utilizations by retaining one or more .of the features that, from the standpoint of the prior art, fairly constitutes-essential characteristics of either the generic or specific aspects of this invention and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims: wedge piece compensates for that variation.

Having thus revealed this invention, I claim as new and desire to secure the following combinations-.- and elements, or equivalents thereof, by Letters Patent ofthe United States:

1. An inserted blade cutter combining a body member having an open sided and open ended blade receiving opening therein, the said opening having a blade seating inner wall inwardly inclined; a blade member insertable in said opening and seating on said inner wall, said blade member, being tapered in the direction of its longitudinalaxis and also tapered in the direction transverse thereto and positioned in said opening with its widest longitudinal edge toward the said inner wall and front end; a wedge member for adapted to be positioned in the said opening ad- -Jacent the blade with its widest portions inward and outward and the longitudinal axis thereof extending in a direction transverse the longitudinal axis of said blade whereby said wedge when moved longitudinally in the direction of its axis crosses the longitudinal axis of the blade and effects clamping of said blade member between the lateral walls of the said opening and in a transverse direction against said inner inclined seating wall of the opening. 2. A metal cutting tool combining a body memberhaving a blade receiving recess therein; a blade and a blade clamping member in said recess, said blade member seating on an inner wall of the recess and said blade receiving recess be ing inwardly inclined with its longitudinal axis rearwardly inclined relative to end and lateral cutting edges formed 'on the blade and said clamp member being inwardly inclined with its longitudinal axis forwardlyinclined relative to said blade member whereby the axes of said two members ,cross each other at an angle of approximately 15, said clamp member in moving in a clamping direction tending to move the'blade member longitudinally along its-inclined seating' surface and simultaneously in a transverse direction firmly against said inner wall of the recess; and interengaging means between said clamp member and a wall of said recess for adjusting said clamp member laterally in the recess in' positive increments thereby to compen'sate for the reduction in thickness of said 7 blade member as the latter is progressively advanced outwardly along its inclined seating surface. I

r -3. A cutting tool combining a body member having a blade receiving recess provided therein; a blade and awedge member insertable in the recess; the said recess having an inner wall inclined relative to the face of the body affording a seating. surface for the blade; the longitudinal axis of said wedge member and blade memberbeing mutually inclined whereby the wedge member diagonally overlaps the blade member at its larger end, said blade seating surface having a clearance aperture formed therein for receiving the said overlapping portion of the wedge member as the clamping surface thereof moves laterally and inwardly to clamped position against the blade.

4. An inserted blade cutter combining a body member having a'blade receiving recess therein, the said recess having an inner wall inwardly incli ned relative to the face of the body; a blade member insertable in said recess and seating on said inner wall, said blade member being tapered in the direction of its longitudinal'axis and also tapered in the direction transverse thereto and positioned in said recess with its widest longitudinal edge inwardly and toward the front end; an

elongated wedge member tapered in the direction of its longitudinal axis and also tapered in the direction transversely thereto positioned in the said recess adjacent the blade with the longitudinal axis thereof extending at an angle to the longitudinal axis of said blade whereby said wedge when moved in the direction of its axis eflects the clamping of said blade member in a transverse direction against said inner inelined seating wall of the recess; said blade and wedge members also having smooth opposed faces and said wedge member having a series of parallel serrations extending in the direction of its longitudinal axis formed on its opposite face; a series of complemental, serrations on the side wall of the body member, said series of serrations atfording means for adjusting said wedge member bodily laterally relative to the blade and posi- Q tively holding said wedge member in laterally adjusted position to compensate for reduction in blade thickness incident to progressive outward adjustment along its inner seating surface and serving as guide means for said wedge member during movement longitudinally in efl'ecting clamping action.

ERNEST REANEY. 

